Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer, unlike RF...

https://wiki-zine.win/index.php/Ultherapy_for_Neck_and_Lower_Face_%E2%80%93_What_Is_%22Advanced_Layering%22%3F

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer, unlike RF which heats skin to 40-45°C for collagen boost. Standard HIFU often treats shallower layers. Thread lifts offer immediate lift but may carry more downtime